Mayor de Blasio is shutting down his controversial non-profit fundraising arm, less than a month after a good government group called for an investigation into whether it is breaking campaign-finance and conflicts-of-interest laws.

Officials overseeing de Blasio’s Campaign for One New York said Thursday that the group has stopped raised funds and is in the process of disbanding.

As of Jan. 15, it had taken in $4.3 million, mostly from unions, real estate firms and other companies that do business with the city.

City Hall sources said that while the mayor believes the nonprofit has broken no laws, he has grown weary of the constant media scrutiny of the group and did not want it to be a distraction heading into his 2017 re-election campaign.

“It’s one less thing he needs to worry about. The nonprofit successfully did what it was created to do, and now it’s time to just move on,” said one political operative.

Lerner on Thursday said her group is “pleased” the nonprofit is shutting because Common Cause “does not accept that secret money is a necessary function of the modern mayoralty.”

“It does not serve the public interest to have a shadow government, serving only to breed mistrust and confusion among voters,” Lerner added. “This is the right decision, which we hope others will follow.”

Donors to the mayor’s re-election campaign and other citywide campaigns are limited to giving $4,950 per election cycle – and only $400 if they do business with the city. Campaign for One New York, however, has received at least 22 donations of $50,000 ore more, including nine for $100,000 and up, records show.

‘It does not serve the public interest to have a shadow government, serving only to breed mistrust and confusion among voters.’

- Susan Lerner, executive director of Common Cause New York

De Blasio, while attending the St. Patrick’s Day Parade, said his non-profit was closing because it had accomplished its mission.

“The work is done. The Campaign for One New York was created to address income inequality. … We feel very good about that work, and we believe we’re on the verge of a great victory.”

As a nonprofit, the group was not required to disclose donors and spending, but did so anyway. It had about $300,000 left as of its last financial disclose filings on Jan.15.

Officials said some of the remaining money would go towards paying off bookkeeping expenses with the rest being moved to the pro-de Blasio nonprofit United for Affordable Housing. Campaign for One New York has previously also funneled money to a national de Blasio-linked nonprofit, The Progressive Agenda.

While Common Cause called for a probe into these groups as well, CONY spokesman Dan Levitan said it was unfair to compare them because both have less direct contact with City Hall and are not run by the same outside consultants.

Leading the donor pack were health care workers’ Local 1199 SEIU and left-leaning hedge fund tycoon George Soros’s nonprofit Fund for Policy Reform Inc., which each gave $500,000.

De Blasio met with Soros’ son Alexander for lunch in Southhampton in August 2015, even taking time to pose for photos that the scion later posted on social media websites. He also met with Soros’ son Jonathan six months earlier, and the Soros family helped arrange for de Blasio to be keynote speaker at the April 2014 Democratic Alliance Conference in Chicago.

De Blasio participated in at least 31 work meetings or phone calls through September with 16 of the 30 major CONY donors — or those directly linked to these donors, records show.

The mayor also attended 23 conferences and other gatherings with CONY contributors — plenty of whom shelled out six-figure donations and regularly do business with the city — and many times publicly showered them with compliments at events.

De Blasio featured these top CONY donors in at least 17 of his office’s press releases, often praising them and providing them a free platform to gain positive media attention.